A present invention relates in general to electric evaporation systems which use wicks, and in particular to a new and useful wick evaporation system having a child-resistant wick retaining structure, a reverse thread feature, unique decorative features and a compact structure.
Wick-based vapor emanation systems are known in the art for dispersing into the air vapors of any number of liquids. Such systems are often used in the home with liquids varying from insect repellent to air freshener. Typically, in such systems, one end of a wick is partially submerged in the liquid to be dispersed. The liquid is contained in any suitable container. The partially submerged portion of the wick absorbs the liquid, some of which diffuses by capillary or wicking action into the exposed, unsubmerged portion of the wick. The exposed portion of the wick is locally heated, often by means of a ring-shaped heater which fits over the wick. This causes the liquid which has diffused into the exposed portion of the wick to evaporate into the surrounding air. Continual application of heat to the exposed portion of the wick results in an evaporation/absorption process that continues until the liquid is consumed.
A problem with conventional wick-based liquid emanation systems, as with many products suitable for home use, is the potential that a child will come into contact with the liquid contents of the system. Many of the liquids utilized with such systems can be harmful if swallowed, and some are harmful if merely touched. Therefore, it is desirable to make these systems "child-resistant " to reduce the chance that a child will access the potentially harmful contents of the system.
U.S. Pat. No. 5,909,845 to Greatbatch, et al. discloses a child-resistant, wick-based liquid emanation system that includes a container which is capable of containing liquid and has an opening. A wick is partially disposed within the container and extends through the opening of the container. A hollow overcap encases the extended portion of the wick and has a closed, separable tip and an open base attached to cover the opening of the container. The system is activated by separating the tip from the overcap. This system is complex and adds a step before the product can be used.
U.S. Pat. Nos. 5,038,394 and 5,290,546 to Hasegawa, et al. disclose an electric air freshener that includes an electric plug which is integral with the vaporizer housing. This structure is common to similar electric evaporators that have been available in Europe and Asia for many years. The housing includes a ring heater for engaging the upper end of a wick for heating that end and vaporizing liquid from a bottle which is screwed into a socket formed as part of the housing.
A similar structure is disclosed in U.S. Pat. No. 5,222,186 to Schimanski, et al. where a tangential heater rather than an ring heater is used as the heating means for heating the upper end of the wick. U.S. Pat. No. 5,222,186 to Schimanski, et al. is incorporated here by reference for its teaching of this type of electric evaporator.
U.S. Pat. No. 5,647,053 to Schroeder, et al. shows a similar structure which can swivel around its plug.
The concept of a wick-based electric evaporator is quite old as demonstrated by U.S. Pat. No. 1,944,821, issued in 1934, and including the same basic units of a wick with an upper end that is heated to vaporize liquid from a container extending below the heater.